In the related art, for example, the electric fuse is mounted on the chip of a semiconductor integrated circuit or the like used in a semiconductor device. The electric fuse is used as a trimming element for adjusting (correcting) characteristics, for example, such as the performance and power consumption of the semiconductor device.
In the electric fuse, a predetermined electric current is caused to flow through a filament thereof, thereby generating a salicide EM (Electro Migration) or Si melting in the filament. As a result, the resistance value of the filament is increased to write (program) information on the electric fuse. Specifically, the resistance value of the filament of the state before the electric current supply is recorded on the electric fuse as information “0”, and the resistance value of the filament after the electric current supply is recorded on the electric fuse as information “1”.
Furthermore, in an electric fuse module of the related art, a technique for performing multi-value recording of information is also suggested (for example, see JP-A-2006-253353). FIG. 21 shows a circuit configuration of the electric fuse module suggested in JP-A-2006-253353.
The electric fuse module 200 of JP-A-2006-253353 includes two electric fuses 212 and 213 having different program characteristics, a switching device 214 for program controlling, a switching device 215 for reading, and three differential amplifiers 216, 217, and 218. One end of each of the two electric fuses 212 and 213 is connected to external power source voltage terminals 210 and 211, respectively, and the other ends thereof are commonly connected to each other. Furthermore, the switching device 214 for program controlling and the switching device 215 for reading are connected in parallel between common connection nodes of the two electric fuses 212 and 213 and a ground terminal. Moreover, three differential amplifiers 216, 217, and 218 detect the voltage level of the common connection node based on reference voltages 219, 220, and 221, respectively.
In the electric fuse module 200 of JP-A-2006-253353, by changing the timing during which the electric fuses 212 or 213 are programmed, a plurality of voltage levels of the connection node between the electric fuse and the switching device are generated. In this way, in the electric fuse module 200 of JP-A-2006-253353, the multi-value information is realized by a minimum circuit size.